|Oil shale areas in Utah, Colorado and Wyoming. Click to enlarge.|
The Bureau of Land Management, part of the US Department of the Interior, has begun public meetings to obtain comments for the programmatic Environmental Impact Statement (PEIS) required to support commercial oil shale and tar sands leasing on federal lands in Utah, Colorado and Wyoming.
Congress directed the BLM to complete the PEIS and initiate commercial leasing of lands for the production of strategic unconventional fuels in the recently passed Energy Policy Act of 2005.
For purposes of the PEIS, the planning area for oil shale includes the Uintah Basin (Utah), the Piceance Basin (Colorado), the Washakie Basin (Colorado and Wyoming), and the Green River Basin (Wyoming). For tar sands, the planning area encompasses certain sedimentary portions of the Colorado Plateau in Utah.
One of major concerns emerging about the production of oil shale is the water issue.
According to a report in the Salt Lake Tribune, a former Utah state science adviser estimated that 10,000 acre-feet of water would be needed to sustain a year of producing 100,000 barrels per day of kerogen.
(One acre-foot is a volume one foot deep covering an area of one acre. An acre-foot contains exactly 43,560 cubic feet, or about 325,851.4 gallons US. One thousand acre-feet (kaf) contains 325,851,400 gallons. The 10 kaf needed for 100 kbpd of kerogen per year would thus require 3.25 billion gallons of water per year.)
Earlier estimates (made during the prior oil-shale boom several decades ago) for water use in surface mining processing of oil shale range from one to three barrels of water for each barrel of kerogen. On that basis, 100,000 barrels per day of kerogen would require between 1.5 billion and 4.6 billion gallons of water per year. So the 10 kaf estimate from Utah basically splits the difference.
Further complicating the picture are the implications for surface and ground water quality.
The Denver Post reports that governments in Colorado and Utah are reviving plans drawn up more than two decades ago during the previous oil-shale boom for major reservoirs to feed shale production.
The town of Rangely is using an environmental study done during the late 1970s as a starting point for a proposal to build a 200 kaf reservoir. That study at the time determined about 500 kaf of White River water would be available for capture and reuse.
|Drought forecast map.|
Using an in-situ process such as Shell has been working on (earlier post) would require less water than the surface method, but a more precise estimate of how much less is still under analysis.
The West has been in the grips of a drought that USGS scientists in 2004 characterized as the worst in 500 years. The drought, while ongoing, is forecast to improve a bit this spring.